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USING HELP

The example program TSTHLP, together with the sample library demo.shl, shows a typical help session. Type the following command:

This will produce an announcement, followed by the question:

Name of help library?

Give the reply:

This will produce a ":" prompt; enter one of the following:

At other prompts, enter: The topic and subtopic names in the library are called ``keywords''. When searching for a given keyword, it is unnecessary to give the full name. The rules for abbreviating keywords are as follows:
  1. The simplest form of abbreviation is to give only the first few characters. Thus "FRED" is a valid abbreviation of "FREDERIC".
  2. A keyword can be made up of one or more ``words'' separated by an underscore. Each such word can be abbreviated individually. Thus "A_D" is a valid abbreviation of "ANNO_DOMINI".
  3. The characters "%" and "*" match, respectively, any single non-space character or any sequence of such characters.
  4. The character "" in the entered string is itself ignored but causes the next character to be accepted literally (but not space). This means that the various special characters can appear in keywords; however, exploiting this feature is not recommended.
  5. If a word from the entered string contains but does not end with a "*" wildcard, it must not be truncated. Thus, although "SAM" and "S*E" are both valid matches for "SAMPLE", "S*PL" is not. This feature allows abbreviations to be used which unambiguously specify the end of the string as well as the beginning.
  6. Neither the keyword in the library nor the string entered may contain leading or embedded spaces.
When the entered string is a valid abbreviation of more than one topic but is not an exact match for any topic, all the matched topics are reported. Thus "* * *" would display all the level-three topics, and "..." would display every topic in the library. When the entered string is an exact match for a topic, no further matches are reported once the exact match has been found.

Keyword comparisons are not case-sensitive: "aBc" is a valid match for "ABC" for example.



next up previous
Next: CREATING A HELP LIBRARY
Up: HLP --- Interactive Help System
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HLP --- Interactive Help System
Starlink User Note 124
P. T. Wallace
13th June 1995
E-mail:ptw@star.rl.ac.uk